The present research program will continue to examine the involvement of the gustatory neocortex in the mediation of the rat's hedonic and associative response to alcohol solutions. Previous data from our labortory have shown that rats lacking gustatory neocortex consume more alcohol than control rats under schedules of restricted fluid access. Experiments are planned to determine if this hyperresponsiveness in rats lacking gustatory neocortex will be present when animals are given continuous access to aclohol. An additional experiment will determine if body weight and consumption of alcohol for caloric content might account for the hyperresponsiveness. Data collected in the last year also indicate that, although rats lacking gustatory neocortex acquire alcohol aversions normally, they extinguish the aversion faster than controls. Similarly, a preoperatively-instated alcohol aversion was retained following gustatory neocortex ablation but, again, the operated rats extinguished faster than controls. These data indicate that alcohol is not a simple tastant but rather has complex properties. Experiments are proposed to test the hypothesis that the odor of alcohol mediates the learning and retention in rats lacking gustatory neocortex. Because alcohol represents a compound taste and odor stimulus, the scope the present grant is broadened to examine both gustatory and olfactory qualities of alcohol. Each of these component stimuli and their neural basis will be examined in associative tests by separate manipulations: The gustatory aspect of alcohol will be degraded as a cue with gustatory neocortex ablations; the odorant qualities of alcohol will be degraded with olfactory bulbectomy. Because consumption of alcohol represents a serious health problem, study of the neural mechanisms which influence drinking behavior is important and may provide insight to methods for the eventual modification of alcohol consumption.